c＃嵌套for循環檢查比較列表中的每個元素返回奇數結果

Question

所以我有這個代碼...這是讓我瘋狂。結果不一致，它取決於列表中對象的順序。

基本上覆制了一個對象列表，使用compareMembers（）（相對於它100％沒有問題）檢查列表中的每個對象，然後如果它們具有比allowed（num）更多的共同點，那麼它們「相似」我們決定刪除哪一個。下一個具有較低分數的人從temp列表中刪除，並在所有迭代後返回temp列表。

例如，如果我排序使用去除類似的現有的列表：

group.Sort((a, b) => -1 * a.GroupScore().CompareTo(b.GroupScore())); 

返回的列表總是中有較少的元素，比當我比較相似，並且該列表是完全隨機的。我知道這個問題在於這一部分......希望它的內容簡單，我只是盯着它太久了。

下面是給出相互衝突的結果的代碼。

public List<MyGroup> RemoveSimilar(List<MyGroup> group, int num) 
    { 
     List<MyGroup> temp = group.ToList(); 

     for(int i = 0; i < group.Count - 1;i++) 
     { 
      for (int j = i + 1; j < group.Count;j++) 
      { 
        if (group[i].compareMembers(group[j]) > num) 
        { 
         if (group[i].score < group[j].score) 
         { 
          temp.Remove(group[i]); 
          break;//removed this one might as well stop checking it 
         } 
         else 
         { 
          temp.Remove(group[j]); 
         } 
        } 
       } 
      } 
     return temp; 
    } 

這裏是MyGroup的類：

public class MyGroup 
{ 
    public Member firstMember; 
    public Member secondMember; 
    public Member thirdMember; 
    public double score; 

    public MyGroup() 
    { 
    } 

    public int compareMembers(MyGroup x) 
    { 

     int i = 0; 

     if (this.firstMember == x.firstMember) 
     { i++; } 
     if (this.secondMember == x.secondMember) 
     { i++; } 
     if (this.thirdMember == x.thirdMember) 
     { i++; } 
     if (this.firstMember == x.secondMember) 
     { i++; } 
     if (this.firstMember == x.thirdMember) 
     { i++; } 
     if (this.secondMember == x.thirdMember) 
     { i++; } 

     return i; 
    } 


    public MyGroup(Member one, Member two, Member three) 
    { 
     firstMember = one; 
     secondMember = two; 
     thirdMember = three; 


     groupScore = firstMember.mScore + secondMember.mScore + thirdMember.mScore; 
    } 

    public double GroupScore() 
    { 

     return score; 
    } 
} 

這裏是被用來彌補本集團成員快速類：

public class Member 
{ 
    public string idNum; 
    public string firstName; 
    public string lastName; 
    public double mScore; 


    public Member() 
    { 
    } 

    public Member(string id, string fnm, string lnm, double pt) 
    { 
     idNum = id; 
     firstName = fnm; 
     lastName = lnm; 
     mScore = pt; 
    } 

    public override string ToString() 
    { return firstName + " " + lastName; } 


    public string Desc() 
    { 
     return idNum + " " + firstName + " " + mScore.ToString(); 
    } 
} 

好了，所以我重新設計它並且似乎得到一致的結果，無論列表的順序如何....仍然想知道爲什麼第一次嘗試不斷搞砸。下面是重新設計的版本：

 public List<MyGroup> RemoveSimilar(List<MyGroup> group, int num) 
    { 
     List<MyGroup> temp = group.ToList();//take group argument and copy it into a new list 

     for (int i = 0; i < group.Count - 1; i++)//first loop through each element of group list 
     { 
      if (temp.Contains(group[i])) //checks to make sure group[i] hasn't already been removed from temp list 
      { 
       for (int j = i + 1; j < group.Count; j++)//second loop through each element to compare to first 
       { 
        if(group[i] != group[j]) //make sure we aren't comparing the same two objects 
        { 
         if (group[i].compareMembers(group[j]) > num)//check to see how "similar" groups are 
         { 
          if (group[i].score < group[j].score)//if the groups are similar, see which has a higher score 
          { 
           temp.Remove(group[i]);//outer element is not the best "unique group" so we remove it 
           break; //removed this one might as well stop checking it 
          } 
          else 
          { 
           temp.Remove(group[j]);//inner element was similar to outter, but not the best so we remove it 
          } 
         } 
        } 
       } 
      } 
     } 
     return temp; //return the list after all similar elements have been removed 
    } 

Answer 1

當你有這樣定義一個函數：

class MyGroup 
{ 
    public int compareMembers(MyGroup x); 
} 

它可以是重要的，當你改變調用對象與參數來考慮的話。您usally想從下面的調用相同的結果：

x.compareMembers(y); 
y.compareMembers(x); 

你的情況，你需要改變功能compareMembers這樣：

public int compareMembers(MyGroup x) 
{ 
    int i = 0; 
    if (this.firstMember == x.firstMember) 
    { i++; } 
    if (this.secondMember == x.secondMember) 
    { i++; } 
    if (this.thirdMember == x.thirdMember) 
    { i++; } 
    if (this.firstMember == x.secondMember || this.secondMember == x.firstMember) 
    { i++; } 
    if (this.firstMember == x.thirdMember || this.thirdMember == x.firstMember) 
    { i++; } 
    if (this.secondMember == x.thirdMember || this.thirdMember == x.secondMember) 
    { i++; } 
    return i; 
} 

作爲一個側面說明函數名可能是更countEqualMembers明確功能的目的。